US6901289B2 - System for providing electrical stimulation to a left chamber of a heart - Google Patents

Abstract

A medical electrical lead is disclosed that is adapted for placement in the coronary sinus, or a branch vein thereof. The lead includes a first and second pace/sense electrode. A selection mechanism is provided to select either the first or the second electrode for use as a cathode, with the other electrode being selected as the anode. According to another aspect of the invention, a high-voltage coil electrode may be provided between the first and second electrodes. The coil electrode may be electrically coupled to the anode to increase the shadow area of the coil electrode.

Description

RELATED APPLICATIONS

This Application claims priority to provisionally-filed U.S. Patent Application Ser. No. 60/258,651 filed Dec. 29, 2000 entitled “Medical Electrical Lead”, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to an implantable medical electrical lead; and more particularly, relates to a medical electrical lead system for implantation in a cardiac vein.

BACKGROUND OF THE INVENTION

It has long been known that implantable medical electrical leads may be positioned transvenously within one or more chambers of the heart to provide electrical stimulation to, and to monitor signals occurring within, the cardiac tissue. In order to achieve reliable sensing of the cardiac electrogram and/or to apply stimulation that effectively paces or cardioverts the heart chamber, it is necessary to accurately position the electrode surface against the endocardium or within the myocardium at the desired site and affix it during an acute post-operative phase until fibrous tissue growth occurs. After implantation, the leads may be coupled to an implantable medical device (IMD) such as a pacemaker or cardioverter/defibrillator so that the desired stimulation may be provided to the cardiac tissue.

More recently, endocardial pacing and cardioversion/defibrillation leads have been developed that are adapted to be advanced into the coronary sinus and branch coronary veins. During this type of implant procedure, a distal end of a lead is advanced through the superior vena cava and the right atrium, and through the ostium of the coronary sinus. The lead may further be advanced within the coronary sinus into one of the branch veins.

Placement of leads within the coronary sinus and branch veins is important because these leads can be located adjacent to the left ventricle or the left atrium of the heart. Electrical stimulation can then be provided to the left chambers of the heart without actually placing one or more leads into these chambers. Because the left side of the heart accounts for the majority of the heart's hemodynamic output, various pathologies may be better treated through such left-heart stimulation. For example, in patients experiencing conditions associated with heart failure, electrical stimulation of both the right and left sides of the heart can be used to re-synchronize the depolarization of the left and right ventricles in a manner that increases the cardiac output.

In addition to providing important benefits to heart failure patients, the location of electrodes within the coronary sinus and branch veins can also reduce defibrillation thresholds. That is, when a shocking electrode is positioned within a left-sided cardiac vein and used in conjunction with other shocking electrodes placed in more traditional locations, a lower shock energy may be required during cardioversion and/or defibrillation therapy. This can reduce the discomfort associated with these therapies.

Several challenges are posed by providing both pacing and defibrillation electrodes within the coronary vasculature. Because of the small vessel size, positioning multiple leads within the vasculature is difficult. Additionally, the size of coil electrodes of the type needed for high-voltage therapies may be limited based on the size of the vessels, thereby limiting the area of the tissue through which current flows during the therapy. This may limit the efficacy of high-voltage therapies. Finally, locating the leads at a precise location needed to provide adequate tissue stimulation may be difficult given the problems associated with navigating the torturous vessels such as the coronary sinus and branch veins.

What is needed, therefore, is an improved system that may be used to provide both pacing and high-voltage therapy to the left chambers of the heart and that may be reliably fixed within a branch vein of the coronary sinus.

SUMMARY OF THE INVENTION

According to one embodiment of the current invention, a medical electrical lead is disclosed that is adapted for placement in the coronary sinus, or a branch vein of the coronary sinus. The lead includes a first electrode located in proximity to the distal end of the lead. A second electrode is located distal to the first electrode. A selection mechanism is provided to select either the first or the second electrode for use as a cathode, with the other electrode being selected as the anode. In one embodiment, the selection mechanism may include a configurable circuit. Alternatively, the selection mechanism may include selectable electrical configurations provided by an adaptor module. After the selection is complete, relative low-voltage electrical stimulation, including pacing pulses, may then be delivered between the anode and cathode to a left chamber of the heart.

The lead of the current invention may include means to aid in the positioning of the lead within the coronary sinus or branch veins. For example, the lead may include a lumen formed within the lead body, or adjacent to an exterior surface of the lead. The lumen is adapted to receive a guidewire or stylet for use in delivering the lead to a target location during implant. In one embodiment, the lumen is formed of a collapsible tube such as tubing formed of a porous PTFE tubing material. The tube is carried adjacent to at least a portion of the outer surface of the lead body.

According to yet another aspect of the current invention, a coil electrode may be positioned between the first and second electrodes. The coil electrode is adapted to deliver relatively high-voltage therapy such as cardioversion/defibrillation shocks to the heart. In one embodiment, the coil electrode may be electrically coupled to the electrode selected as the anode to increase the shadow area of the coil electrode during high-voltage stimulation therapy.

In another embodiment of the invention, a method of delivering electrical stimulation to a heart is provided. The method includes the step of delivering a lead to a branch vein of the coronary sinus, wherein the lead includes first and second pace/sense electrodes coupled to a distal end of the lead. The method further includes selecting one of the first or the second pace/sense electrode as a cathode, and delivering electrical stimulation between the cathode and the other pace/sense electrode to a left chamber of the heart. The lead may further include a coil electrode for delivering relatively high-voltage stimulation to the heart. In this embodiment, the method may further include electrically coupling one of the pace/sense electrodes to the coil electrode prior to the delivery of the high-voltage therapy to increase the shadow area of the coil electrode.

In still another embodiment of the invention, a system is provided delivering electrical stimulation to a heart. The system includes a lead having first and second pace/sense electrodes, and a coil electrode. The system may further include an adapter for selecting one of the first and the second pace/sense electrodes as a cathode for delivery of pacing therapy. The adapter may further couple the other one of the pace/sense electrodes to the coil electrode for use as the anode, and further for delivery of relatively high-voltage stimulation. As an alternative to the adapter, the system may include an implantable medical device having means for selectably configuring the electrodes in the afore-mentioned manner.

Other scopes and aspects of the current invention will become apparent to those skilled in the art from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of one embodiment of the inventive lead system.

FIG. 2 is a side cutaway view of one embodiment of the distal portion of the lead.

FIG. 3 is a posterior view of the heart illustrating the inventive lead system implanted within a branch vein of the coronary sinus.

FIG. 4 is a block diagram of an IMD configuration including a programmable switch as may be used with the lead system of the current invention.

FIG. 5 is a side view of a lead that is similar to that shown inFIG. 2 including a multi-pin connector as may be used with the current invention.

FIG. 6 is an end view of the connector of FIG.5.

FIG. 7 is an end view illustrating a mating interface for use with the connector of FIG.

FIG. 8 is a side view illustrating use of the mating interface ofFIG. 7 incorporated within an adapter that includes a standard DF-1 connector.

FIG. 9 is a side view illustrating use of mating interface incorporated within an adapter that includes a standard IS-1 connector.

FIG. 10 illustrates an adapter as shown inFIG. 9 coupled to a lead including the connector shown in FIG.5.

FIG. 11 illustrates an adapter such as shown inFIG. 9 being coupled to a lead of a type as shown in FIG.5.

FIG. 12 is an end view of the connector ofFIG. 5 being temporarily configured for threshold testing.

DESCRIPTION OF THE INVENTION

The present invention provides a single lead system adapted for placement within a branch vein of the coronary sinus. This system is specifically sized to fit within the length and width of the branch vein.

FIG. 1 is a plan view of one embodiment of the inventive lead system. The lead includes anelongated body10 that may be of any conventional lead construction known in the art. For example, the exterior of lead may be formed of silicone, polyurethane, or a non-porous or dense PTFE.

The distal end of the elongated body includes atip electrode12 for pacing and sensing in the left ventricle. This electrode could be any of the various types of pacing electrodes known in the art such as a porous platinized electrode assembly. A tip electrode is shown, although a ring electrode located proximate the distal end of theelongate body10 could be used in the alternative. In one embodiment, this electrode is a steroid-eluting porous pacing electrode, as described in commonly-assigned U.S. Pat. Nos. 4,506,680, 4,577,642; 4,606,118 incorporated herein by reference. The electrode may be constructed of porous, sintered platinum, titanium, or a similar bio-compatible metal.

Tip electrode12 could include means to aid in fixing the electrode assembly at a desired site of implant within the branch vein. For example, the electrode could include flexible tine-like or fin structures. Fixation devices of this nature are disclosed in U.S. Pat. Nos. 5,964,795, 6,006,122, and 5,387,233 which are incorporated herein by reference. Alternatively, thelead body10 could be shaped to have side-to-side undulations to wedge the lead within the vessel and aid in retaining the lead body at the implant site.

Shocking electrode16, located proximal totip electrode12 provides cardioversion/defibrillation stimulation, and, in one embodiment, may be used as an anode for bipolar pace/sense therapy in conjunction with the pace/sense cathode, as will be discussed further below.Shocking electrode16 is a coiled electrode that may be of any construction known in the art. In one embodiment, the coil is isodiametric with respect to the lead body. Such isodiametric electrode coils may be molded into the electrode body or the coils may be machined to provide a flush surface. This is described in U.S. Pat. No. 4,161,952, issued to Kinney et al. Similarly, U.S. Pat. No. 5,957,970 to Shoberg discloses an isodiametric defibrillation lead as may be used with the current invention. The lead described in the '970 patent is manufactured by removing a portion of an extruded tubular lead body in the region of the coil so that the electrode is flush with the surface of the lead.

Shocking electrode16 may be encased in a layer of porous PTFE material or expandable PTFE (ePTFE), as shown in FIG.2. Theporous PTFE jacket30 is designed to prevent tissue in-growth around the coils of the shocking electrode.Shocking electrode16 is electrically coupled to a conductor23 (shown dashed) extending to aconnector pin45 at the proximal end of the lead. The associatedconnector44 may be of any type known in the art, including a DF-1 industry standard connector.

In one preferred embodiment of the current invention,elongate body10 may further include aring electrode18. InFIG. 1, this electrode is shown located just proximal to theshocking electrode16, although it may be positioned distal to theshocking electrode16 in another embodiment. Pacing pulses may be delivered betweentip electrode12 andring electrode18. Additionally,ring electrode18 may be used as the pace/sense cathode if the location of ring electrode is more favorable for such therapy than the most distal electrode. If thering electrode18 is selected as the pace/sense cathode,tip electrode12 may be electrically coupled in common with theshocking electrode16 to augment the shadow area of the shocking electrode. Similarly, if the mostdistal electrode12 is selected to be the pace/sense cathode, thering electrode18 may be electrically coupled with theshocking electrode16.

In the illustrated embodiment,conductors21 and25 extend to pinconnector49 andring connector47, respectively.Connector46 may be any type of proprietary or industry-standard connector known in the art. For example, the connector may be an industry-standard IS-1 connector.

As noted above, the construction of the lead body may be of any type known in the art.Conductors21,23, and25 may be of a cable or coil design, and may reside within individual lumens formed in the insulation. In another embodiment, one or more of the conductors may be coils positioned coaxially with respect to each other, with insulation provided between adjacent coils. In yet another embodiment,lead body10 carries a drawn brazed stranded (DBS) cable insulated with FEP.

The lead body may further include a lumen for receiving a stylet. For example, one of theconductors21,23 and25 may be coiled to define such a lumen, or the lumen may be formed within the insulation. In yet another embodiment, the lumen may extend through the distal end ofelongate body10 andtip electrode12. In this instance, a guidewire may be advanced beyond the lead distal tip for positioning the lead body within the coronary sinus or a branch vessel. In this embodiment, atip seal13 may be provided at the distal end of the lumen, as described in commonly-assigned U.S. Pat. No. 6,192,280 incorporated herein by reference. This tip seal prevents the ingress of bodily fluids into the lumen.

According to one aspect of the invention, predetermined portions of the elongatelead body10 may be coated at one or more locations with a porous Polytetrafluoroethylene (PTFE) material such as expanded PTFE (e-PTFE). As discussed in commonly-assigned U.S. patent application Ser. No. 09/827,103 filed Apr. 5, 2001 entitled “Implantable Medical Device Adapted to Promote Selected Tissue In-Growth and Method for Making the Same”, incorporated herein by reference, porous PTFE having a relatively large pore size may be used to selectively promote tissue in-growth. Because of the tissue in-growth, portions of the lead coated with PTFE swell after implant. By selectively coating thelead body10 in predetermined locations such as atlocations19aand19b, this swelling effect urgeselectrodes12,16 and18 against a vessel wall. This promotes capture, and retains the lead at a desired location of implant.

Thelead body10 ofFIG. 1 is further shown having aside lumen32 offset from the surface of the lead body. This side lumen may extend from the proximal lead end to any desired location at the distal end of the lead body. For example, the lumen may extend to tipelectrode12. Thisside lumen32 may be formed of PTFE such that the inner lumen is collapsible. For example, a PTFE tube may be affixed to thelead body10 using any type of bio-compatible adhesive. The lumen expands to fit over a guide wire positioned in the venous anatomy for the purpose of directing the lead to the site of implant. When the guide wire is removed, the lumen will collapse or fold down against thelead body10. The distal end of the lumen may be closed, or astop member33 may be provided at the lumen distal end to prevent a stylet advanced within the lumen from extending beyond the lumen distal end and possibly damaging tissue.

According to yet another aspect of the invention, additional collapsible PTFE lumens as may be formed of PTFE tubing may be added around the lead body. Each of these tubes will further selectively promote tissue in-growth, and, may be positioned to urge one or more of the electrodes against tissue after the implant procedure. These additional lumens may further be used during an implant procedure in conjunction with a guidewire or stylet to steer a lead around a curve within the vascular system.

In one embodiment, the distal end of the lead body is sized to be positioned within a branch vein as a means of fixation. In this embodiment, the diameter oflead body10 may range from approximately 0.030″ to 0.090″, and in a more specific embodiment may range from approximately 0.040″ to 0.065″. In such an embodiment, all electrodes have a diameter similar to that of the lead body to allow for placement of the lead within the coronary vessels.

FIG. 2 is a side cutaway view of one embodiment of the distal portion of the lead. Theshocking electrode16 of this embodiment is positioned betweentip electrode12 andring electrode18. This electrode may have a length in the range of approximately 2 to 4 cm and a shadow area in the range of 70 to 200 mm². Thetip electrode12 andring electrode18 may be spaced approximately 8 to 12 mm from either end of the shocking electrode in one embodiment of the invention. The length of the tip and ring electrodes may each range from approximately 4 to 10 mm, although other dimensions may also be utilized. Each electrode may having a surface area ranging from approximately 20 to 48 mm², although again, other sizes may be utilized Since theshocking electrode16 is downsized to fit within a branch vein, the electrical coupling of the shocking electrode with either thetip electrode12 or thering electrode18 provides additional current distribution during cardioversion/defibrillation to increase shocking efficacy. The entire surface of tip and ring electrodes may be conductive, howeverzones50 and52, respectively, may be provided on the surfaces of each electrode to create a more conductive and effective interface with the tissue for pacing. These zones, which may be annular, have specialized surfaces that may be of a porous and platinized platinum. The surfaces may also be steroid eluting, as described in U.S. Pat. No. 4,506,680 to Stokes, and related U.S. Pat. Nos. 4,577,642; 4,606,118; and 4,711,251, all commonly assigned to the assignee of the present invention and incorporated by reference herein in their respective entireties. Because thespecialized zones50 protrude radially from the tip and ring electrodes, these zones come into intimate contact with the heart wall when the lead is wedged within the confined space of a cardiac vein.

The conductors to each of theseelectrodes21 and25 may be connected directly to the end of the electrodes carrying thisspecialized surface50 in order to maintain the best efficiency in delivering current to these zones for pacing. The length ofspecialized surface50 may range from approximately 0.5 to 3 mm and the surface area from approximately 1 to 6 mm². Further,tip electrode12 may have a tapered tip extending from the specializedzone50. This tip adds to the shadow area of theelectrode12 in order to augmentelectrode16 for high voltage shocking if this electrode is selected as the pacing anode. Moreover, if tip electrode is selected as the cathode, this tip does not drain excessive current when low voltage pacing pulses are delivered. Similarly, in the case ofring electrode18, theportion18aof the electrode may be a polished conductive surface that is less conductive and slightly smaller in diameter thanring52.Portion18aofring electrode18 may augment the electrode for high voltage shocking but does not drain excessive current from low voltage pacing pulses ifring electrode18 is selected as the cathode.

In the embodiment shown inFIG. 2, theproximal portion18aofring electrode18 may be formed of a coiled construction that provides better flexibility and strain relief over a longer length, so that the lead body may bend with less stress in the cardiac venous anatomy. The coil could be made of platinum or platinum clad tantalum or any material such as is known to the art and would be joined to the ring by a weld such as is known in the art.

The lead of the current invention may further include one or more radiopaque marker bands at the distal end such asmarker band53. This aids in placing the distal end of the lead during the implant procedure as discussed below.

FIG. 3 is a posterior view of the heart illustrating the inventive lead system implanted within a branch vein of the coronary sinus.Branch vein60 may be any of the branch veins draining into thecoronary sinus62, including the posterior lateral vein (PLV), lateral vein, or great cardiac vein (GCV).

Positioning of the lead may be completed using several methods. During the implantation procedure, a guide catheter may be used to cannulate the ostium64 (shown dashed) ofcoronary sinus62. A guidewire may then be pre-loaded intoside lumen32, and the guidewire and lead may be delivered within the lumen of the guide catheter into thecoronary sinus62. Thereafter, the guidewire may be advanced beyond the distal tip of the lead and navigated into the selected branch vein. This process may be aided using fluoroscopy. A radiopaque marker such as marker53 (FIG. 2) may be provided on a distal end of the guidewire and/orlead body10 to aid in this process, for example. The guide catheter provides back up support for the navigation of the guide wire and lead during the location of the branch vein. After placement of the lead at the target location, the guidewire and guide catheter may then be removed from the body.

In another embodiment wherein theside lumen32 includes a closed distal end, a stylet may be pre-loaded in the lumen, and the lead and stylet combination advanced within the lumen of the guide catheter to thecoronary sinus62. Thereafter, the stylet may be used to advance the lead distal end past the guide catheter distal end and into the desired branch vein. The guide catheter and stylet may then be removed from the body.

In yet another embodiment, the lead need not include a side lumen, but instead includes a lumen within the lead body, as may be defined via a coiled conductor in the manner discussed above. A stylet may be pre-loaded into this internal lumen so that the lead and stylet may be advanced into the coronary sinus in the manner discussed above, and thereafter positioned within a branch vein. According to yet another embodiment of the invention, the internal lead lumen may extend through the distal end of the lead, and a guidewire may be used to place the lead in a manner similar to that discussed above with respect to the side lumen. That is, after the guidewire and lead are positioned within the coronary sinus, the guidewire is advanced to subselect the branch vein, and the lead is then tracked over the guidewire to the target destination. The guidewire and guide catheter are thereafter removed from the body.

As shown inFIG. 3, the distal portion of the lead may be positioned withtip electrode12 wedged into branch vein such that theshocking electrode16 extends proximally along the vein and withring electrode18 positioned near the location where the branch vein drains into the coronary sinus. Another lead70 having a pace/sense electrode pair72 and adefibrillation coil74 may be implanted in the right ventricular apex. When a high-voltage shock is deliver, current flows between defibrillation coils16 and74 alongshock path76. By electrically coupling either thetip electrode12 or thering electrode18 to the defibrillation coil during the delivery of the shock, the current path may be widened to affect more tissue, increasing efficacy of the therapy.

After the leads are positioned within the patient, they may be coupled to an implantable medical device (IMD)80. The implanting physician may then perform electrical testing to determine whethertip electrode12 orring electrode18 provides the best location for biventricular pacing. Temporary contacts can be made with the connectors at the proximal end of the lead to test the mostdistal electrode12 versus the mostproximal electrode18 as the cathode with the other two electrodes serving as the anode. Selection of the cathode is based on the efficiency of bi-ventricular pacing. This selection can be made by programming the pulse generator, or by providing a separate jumper connector to a pin grid array at the proximal end of thelead body10.

FIG. 4 illustrates an IMD configuration including a programmable switch as may be used with the lead system of the current invention. In this embodiment, IMD includes a pace/sense circuit100 to deliver pacing pulses, and to sense cardiac signals. This circuit may include one or more output amplifiers and input amplifiers, and may be any of the configurations known in the art. This circuit may further include an analog-to-digital converter to convert sensed analog cardiac signals to digital signals. The IMD further includes a high-voltage circuit102 for delivering high-voltage stimulation to a coil electrode such asshocking electrode16. This circuit may include one or more high-voltage capacitors and/or charging circuits as is known in the art. The timing, voltage and current levels, and other parameters associated with pace/sense circuit100 and high-voltage circuit102 are controlled bycontrol circuit112.

Both the pace/sense circuit100 and the high-voltage circuit102 are coupled to aselect circuit104, which may be any combination of discrete components, integrated components, and/or one or more encoders and/or multiplexers. Additionally, or alternatively, Micro-Electrical-Mechanical systems (MEMs) technology may be incorporated within the switching circuit. MEMs switches are described in commonly-assigned U.S. patent application Ser. No. 10/004,025 filed Oct. 31, 2001 and incorporated herein by reference in its entirety.Select circuit104electrically couples lines106 and108 selectively tooutput lines110.Select circuit104 may be configured bycontrol circuit112.

IMD80 further includes aprocessing circuit114, which may be a microprocessor or another digital or analog processing circuit as is known in the art.Processing circuit114 is coupled tostorage circuit116, which may include Random Access Memory (RAM), Read-Only Memory (ROM), and/or any other type of storage circuit known in the art. This storage circuit may store operational parameters such as stimulation parameters, and/or programmed instructions executed by processingcircuit116.Processing circuit116 may further be coupled to acommunication circuit120, which may be a telemetry circuit for performing wireless communication transfers to anexternal device122. External device may be a programmer, or any other type of external device for monitoring, programming, or in any other way interacting withinIMD80.

As described above, after lead implantation is completed, a physician may conduct testing to determine whether thetip electrode12 orring electrode18 are associated with better pacing thresholds, and should therefore be selected as the cathode. After this determination is complete,control circuit112 can be programmed to configureselect circuit104 so that signals lines shown collectively asline106 are coupled tooutput lines110 to achieve the desired configuration. The programming ofcontrol circuit112 can be accomplished via a communication transfer fromexternal device122 tocommunication circuit120, and, in the current embodiment, a subsequent transfer of configuration data from processingcircuit116 to controlcircuit112. Similarly, prior to the delivery of a high-voltage shock,control circuit112 may configureselect circuit104 such that either the tip or ring electrode are electrically coupled toshocking electrode16 to thereby increase the shadow area of this electrode, and, in turn, maximize the tissue area affected by the delivered current. This coupling of tip or ring electrode toshocking electrode16 may be performed during pacing therapy as well, if desired, such that the shocking electrode serves as an anode.

In another embodiment of the invention, the coupling of electrodes may be performed at the connector module instead of via an electronic circuit withinIMD80. According to this embodiment, the coupling configuration of electrodes is not generally adapted to be modified during therapy delivery, as is discussed below.

FIG. 5 is a side view of a lead that is similar to that shown inFIG. 2 including a multi-pin connector as may be used with the current invention. The lead is shown to include threeconductors21,23, and25, each coupled to a respective electrode in the manner discussed above. These conductors may be any type known in the art, including cable or coil conductors. Each of the conductors is electrically coupled to a respective connector pin ofconnector140. For example,shocking conductor23 is coupled to pin146,conductor21 is coupled to pin142, andconductor25 is coupled to a third pin (not shown inFIG. 5.)FIG. 5 further shows alockout member149 to be discussed further below.

FIG. 6 is an end view ofconnector140, illustrating connection members shown aspins142,146, andadditional pin148, which is electrically coupled toconductor25. This view further illustrateslockout feature149. In this embodiment, the pins ofconnector140 are equidistant from one another. These pins may be joined to a mating interface on a connector assembly in several different orientations, as illustrated inFIGS. 7 and 8.

FIG. 7 is an end view of amating interface160 for use withconnector140 of FIG.6. The mating interface includes afirst port162 that is circular to receive the pin that is electrically coupled to the electrode selected to be the cathode. As discussed above, since eithertip electrode12 orring electrode18 will be selected as the cathode,first port162 will therefore be coupled to either pin142 or148. Thesecond port164 is oblong, and is designed to mate with, and electrically couple to, the remaining two pins. That is,port164 will receive eitherpins146 and142, or pins146 and148. The two options are shown by dashedlines150 of FIG.6.Lockout member149 may optionally be provided as a protruding ridge betweenpins142 and148 to preventmating interface160 from receiving the combination ofpins142 and148, since this would selectshocking electrode16 as the pacing cathode, with the remaining two electrodes selected to deliver high-voltage shocks.

FIG. 8 is a side view illustrating use ofmating interface160 incorporated within an adapter that includes a standard DF-1connector200 at the proximal end.Mating interface160 is shown in cross-section to illustrate the various electrical connections associated with the adapter, although it will be appreciated that this mating interface is actually included within adistal end202 of the adapter.

Dashedlines204 illustrate the electrical connections associated with the ports ofmating interface160.Port164 is electrically coupled toconnector pin206 andring connector208 of adapter viaconductors210 and212, respectively. Similarly,port162 is electrically coupled to pinconnector214 viaconductor216. By selectively couplingport162 to either pin142 or148 ofconnector140, then couplingpins206 and208 to a connector block of a pacemaker cardioversion/defibrillator as is known in the art, the desired electrical connections as determined by threshold testing may be obtained. A high-voltage shock may then be delivered viapin206 andconductor210, whereas pacing therapy may be delivered viapin214, with the return current path being provided bypin connector206 andring connector208.

FIG. 9 is a side view illustrating use ofmating interface160 incorporated within an adapter that includes a standard IS-1connector230 at the proximal end. As withFIG. 8,mating interface160 is shown in cross-section to clarify the electrical connections, and it will be appreciated the mating interface is actually included within thedistal end232 of adapter. Dashedlines234 illustrate the electrical connections associated withmating interface160.Port164 is electrically coupled toring connector238 of adapter viaconductor240. Similarly,port162 is electrically coupled to pinconnector244 viaconductor246. By selectively couplingport162 to either pin142 or pin148 ofconnector140, then couplingpin connector246 andring connector238 to a connector block of a pacemaker as known in the art, the desired electrical connections as determined by threshold testing may be obtained. In this embodiment, pacing therapy may be delivered viapin244, with the return current path being provided byring connector238. As will be appreciated, in this embodiment, shocking electrode16 (FIG. 1) is used only as the anode for pacing therapy, and is not utilized to delivery high-voltage therapy.

AlthoughFIGS. 8 and 9 contemplate the use of adapters that include industry-standard connectors such as IS-1 and DF-1 connections, this need not be the case, and any type of industry-standard or non-standard connector may employ themating interface160.

FIG. 10 is a side view of an adapter that is similar to that shown inFIG. 9, and which further includes a roll-back sleeve250. This sleeve may be formed of a flexible, biocompatible polymer such as silicone or polyurethane, and is rolled over the proximal end of a lead such as a lead shown in FIG.5. This forms a hermetic seal that prevents fluid ingress around the connector pins ofconnector140 and the ports ofmating interface160.

FIG. 11 illustrates an adapter such as shown inFIG. 9 being coupled to alead254 of a type as shown in FIG.5. In this view, roll-back sleeve250 is in a folded, or “rolled-back”, position to allow for easy connection betweenconnector140 andmating interface160. After this connection is made, roll-back sleeve is unfolded to a position similar to that shown in FIG.10. In this position, roll-back sleeve extends overconnector140, and further over theproximal end252 oflead254. Also shown inFIG. 11 is anoptional suture sleeve256 coupled to lead254 to allow the sleeve to be sutured to tissue so that lead position is maintained at the lead proximal end.

As noted above, to determine the optimal configuration for a lead according to the current invention, threshold testing must be performed. During this testing, various pins ofconnector140 must be temporarily coupled. This can be accomplished using adaptors having clips similar to “alligator” clips.

FIG. 12 is an end view ofconnector140 showing temporary electrical coupling ofpin146 to pin142 using aclip260.Clip260 is coupled to a distal end oflead262. Proximal end of lead262 (not shown) may be coupled to pulse generation equipment suitable for performing threshold testing during the implant procedure. Similarly,clip264 is temporarily coupled to pin148 so that proximal end oflead266 may be coupled to pulse generation equipment for testing purposes.

The above-described invention provides an improved system for stimulating the left side of the heart. It will be appreciated that other modifications and adaptations within the scope of the invention may be contemplated by those skilled in the art. Therefore, the above discussion are to be considered exemplary in nature, and not limiting.

Claims (34)

1. A medical electrical lead to provide electrical stimulation to a heart, comprising:

an elongated lead body having a proximal portion and a distal portion;

a first pacelsense electrode coupled to the distal portion adapted to provide stimulation to a left chamber of the heart;

a coil electrode coupled to the distal portion proximal to the first pace/sense electrode adapted to provide cardioversion/defibrillation stimulation; and

a second pace/sense electrode coupled to the distal portion and being proximal to the coil electrode,

wherein the elongate lead body provides at least one lumen extending at least a portion of the length of the elongate lead body, the at least one lumen includes a lumen adjacent to an exterior surface of the lead body, and the lumen adjacent to the exterior surface of the lead body is formed of a collapsible tube.

2. The lead ofclaim 1, and further including a connector coupled to the proximal portion to allow either the first or the second pace/sense electrode to be selected as a cathode for delivery of relatively low-voltage stimulation to the left chamber of the heart.

3. The lead ofclaim 2, wherein the connector is adapted to allow the other of either the first or the second pace/sense electrode to be electrically coupled to the coil electrode.

4. The lead ofclaim 1 wherein the lumen adjacent to the exterior surface of the lead body is closed at the distal end.

5. The lead ofclaim 1, and further including a stop member proximate the distal end of the lumen adjacent to the exterior surface of the lead body.

6. The lead ofclaim 1, wherein the second pace/sense electrode is a coil electrode.

7. The lead ofclaim 1, wherein the first pace/sense electrode is a tip electrode coupled to the distal tip of the elongate lead body.

8. The lead ofclaim 7, wherein the tip electrode includes a tapered tip.

9. The lead ofclaim 1, wherein at least one of the first and the second pace/sense electrodes includes a zone protruding from the surface of the first and the second pace/sense electrodes to couple to tissue.

10. The lead ofclaim 9, wherein the zone is a protruding annular ring.

11. A medical electrical lead to provide electrical stimulation to a heart, comprising:

an elongated lead body having a proximal portion and a distal portion;

a first pace/sense electrode coupled to the distal portion adapted to provide stimulation to a left chamber of the heart;

a coil electrode coupled to the distal portion proximal to the first pace/sense electrode adapted to provide cardioversion/defibrillation stimulation; and

a second pace/sense electrode coupled to the distal portion and being proximal to the coil electrode, wherein the elongate lead body has at least one portion of en exterior surface including a porous Polytetrafluoroethylene (PTFE) material.

12. The lead ofclaim 11, wherein the at least one portion is located proximate to any of the first or the second pace/sense electrodes or the coil electrode.

13. A system for providing electrical stimulation to a heart, comprising:

an elongated lead body having a proximal portion and a distal portion;

a first pace/sense electrode coupled to the distal portion adapted to pace a left chamber of the heart;

a coil electrode coupled to the distal portion proximal to the first pace/sense electrode adapted to provide cardioversion/defibrillation stimulation to the heart;

a second pace/sense electrode coupled to the distal portion and positioned proximal to the coil electrode;

a connector coupled to the proximal portion to allow either the first or the second pace/sense electrode to be selected as a cathode to deliver relatively low-voltage electrical stimulation to the left chamber of the heart, wherein the connector is adapted allow the other of either the first or the second pace/sense electrode to be electrically coupled to the coil electrode; and

an adapter to couple to the connector to select either the first or the second pace/sense electrode as a cathode for delivery of the relatively low-voltage electrical stimulation, wherein the adapter includes a roll-back sleeve.

14. The system ofclaim 13, and further including an implantable medical device (IMD) to electrically couple to at least two electrodes selected from the group consisting of the first and the second pace/sense electrodes and the coil electrode.

15. The system ofclaim 14, wherein the IMD includes a select circuit to select either the first or the second pace/sense electrode as a cathode for delivery of the relatively low-voltage electrical stimulation.

16. The system ofclaim 15, wherein the select circuit includes a circuit to select the other of the first or the second pace/sense electrode as an anode for delivery of the relatively low-voltage electrical stimulation.

17. The system ofclaim 16, wherein the select circuit includes a circuit to electrically couple the other of the first or the second pace/sense electrode to the coil electrode.

18. The system ofclaim 13, wherein the adapter is adapted to select the other of the first or the second pace/sense electrode as en anode for delivery of the relatively low-voltage electrical stimulation.

19. The system ofclaim 18, wherein the adapter is adapted to electrically couple the other of the first or the second pace/sense electrode to the coil electrode.

20. The system ofclaim 18, wherein the adapter includes a standard IS-1 connector.

21. The system ofclaim 19, wherein the adapter includes a standard DF-1 connector.

22. The system ofclaim 13, wherein the connector includes at least three connection members adapted to be received by the adapter.

23. The system ofclaim 22, wherein each of the at least three connection members are spaced substantially equidistantly from the other of the at least three connection members.

24. A system for providing electrical stimulation to a heart, comprising:

an elongated lead body having a proximal portion and a distal portion;

a first pace/sense electrode coupled to the distal portion adapted to pace a left chamber of the heart;

a coil electrode coupled to the distal portion proximal to the first pace/sense electrode adapted to provide cardioversion/defibrillation stimulation to the heart; and

a second pace/sense electrode coupled to the distal portion and positioned proximal to the coil electrode;

a connector coupled to the proximal portion to allow either the first or the second pace/sense electrode to be selected as a cathode to deliver relatively low-voltage electrical stimulation to the left chamber of the heart, wherein the connector is adapted to allow the other of either the first or the second pace/sense electrode to be electrically coupled to the coil electrode; and an adapter to couple to connector to select either the first or the second pace/sense electrode as a cathode for delivery of the relatively low-voltage electrical stimulation, wherein the connector includes at least three connection members adapted to be received by the adapter, and wherein the adapter includes a first port to couple to two of the at least three connection members, and a second port to couple to one of the at least three connection members.

25. The system ofclaim 24, wherein the adapter includes a lockout member to prevent a predetermined two of the at least three connection members from coupling to the first port.

26. A method of delivering electrical stimulation to a heart, comprising the steps of:

a.) delivering a lead to a branch vein of the coronary sinus, wherein the lead comprises:

an elongated lead body having a proximal portion and a distal portion;

a first pace/sense electrode coupled to the distal portion; and

a second pace/sense electrode coupled to the distal portion and positioned proximal to the first pace/sense electrode;

b.) selecting one of the first or the second pace/sense electrode as a cathode and the other of the first or the second pace/sense electrode as the anode; and

c.) delivering relatively low-voltage electrical stimulation between the cathode and the anode to a left chamber of the heart, wherein the lead includes a lumen, and wherein step a.) includes guiding the lead with a delivery device positioned within the lumen, and wherein the lumen is a collapsible tube adjacent to an exterior surface of the lead.

27. The method ofclaim 26, wherein the lead further comprises a coil electrode coupled to the distal portion and positioned proximal the first pace/sense electrode and distal to the second pace/sense electrode, and further comprising:

electrically coupling the other of the first or the second pace/sense electrode to the coil electrode prior to step c.).

28. The method ofclaim 27, and further including delivering relatively high-voltage electrical stimulation via the coil electrode.

29. The method ofclaim 28, wherein the step of delivering relatively high-voltage electrical stimulation via the coil electrode is performed after electrically coupling the other of the first or the second pace/sense electrode to the coil electrode.

30. The method ofclaim 26, and further including coupling an implantable medical device (IMD) to the lead, wherein the IMD includes a select circuit, and wherein step b.) includes configuring the select circuit.

31. The method ofclaim 24, wherein step b.) includes coupling the lead to an adapter.

32. The method ofclaim 26, wherein the tube is formed of porous PTFE material.

33. The method ofclaim 26, wherein the delivery device is a stylet.

34. The method ofclaim 26, wherein the delivery device is a guidewire.

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